Timing Belt: 12V 2.8 (LONG procedure)

[Elliott Potter]

Hi Chris!

> > If you were doing this the right way, you would have
> > loosened the camshaft sprockets to get this tension exactly right.
> > We'll assume that it was already good.  If that's not a safe assumption,
> > one of our resident list mechanics can correct me here.  
> 
> When I first read through this writeup, I was mentally nodding as I went
> down the list, but the cam locking tool bit set off my warning alarm. The
> tensioner is offset to the RF side of the engine, effectively tensioning
> only that "leg" of the tbelt when you adjust it. The tool allows you to
> maintain cam orientation and still loosen the sprockets on the cams that the
> belt rides on. This is necessary as they will want to move(freewheel) while
> you tension the belt. Tightening the sprockets back down on the cams after
> the adjustment keeps everything in order. The sprockets are a taper fit to
> the cam, no keyway, and require a puller to free them. It's a bit of a heart
> stopping procedure the first time around. I've got a cheesy Sears two jaw
> puller that does the job with a sacrificial safety nut on the end, so as not
> to mar the cam. It takes a fair bit of pull to loosen a stuck sprocket, and
> they come off with a good quality CRACK!
 
Definitely a heart-stopping moment.  Especially on my 90, with the long
bolt on the puller sitting right on the radiator, I thought I was in for
a few more repairs...

> Anyhow, the point being that I don't think you can get an accurate belt
> tension with having the cam sprockets loosened to freewheel, and the locking
> tool in place to keep the cams TDC'd. YMMV

You're absolutely right that you can't accurately tension the entire
system of cam sprockets/water pump + crank sprocket without loosening
the camshaft sprockets.  The reason I felt relatively comfortable
skipping this step was that in my (very limited) experience, the belt I
removed appeared to have not stretched a noticeable amount, and when the
new belt was put on it appeared to have the same tension on all sides. 
None of these involved very high mileages, though one had a seizing
water pump.

So my instructions were based on the assumption that the old belt was
properly tensioned already, and the new belt wouldn't require such
precise re-tensioning.  However if I was reading all of this, I'd be
more inclined to agree with Chris than Me (I've cc'd Dave Torrey to make
sure he got this...hi again Dave) so I'll consider myself corrected
here.

Thanks for the heads up!
--
Elliott